The scotopic/photopic ratio (S/P) is a parameter that may be considered in the design of road lighting. This paper compares the S/P ratio and correlated colour temperature (CCT) for 297 light source spectra identified in IES Technical Memorandum TM-30-15 to test the assumption that higher S/P ratios demand higher CCTs. The results suggest that, for a given lamp type, there is a strong association between S/P ratio and CCT, and hence that for a given CCT only a small variation in S/P ratio is available. However, the results also suggest that a larger variation in S/P ratio is possible if the lighting designer is able to consider a change in lamp type.

In humans and most other species, changes in the intensity and duration of light provide a critical set of signals for the synchronisation of the circadian system to the astronomical day. The timing of activity within the 24 h day defines an individual's chronotype, i.e. morning, intermediate or evening type. The aim of this study was to investigate the associations between environmental light exposure, due to geographical location, on the chronotype of university students. Over 6 000 university students from cities in the Northern Hemisphere (Oxford, Munich and Groningen) and Southern Hemisphere (Perth, Melbourne and Auckland) completed the Munich ChronoType Questionnaire. In parallel, light measures (daily irradiance, timing of sunrise and sunset) were compiled from satellite or ground stations at each of these locations. Our data shows that later mid-sleep point on free days (corrected for oversleep on weekends MFSsc) is associated with (i) residing further from the equator, (ii) a later sunset, (iii) spending more time outside and (iv) waking from sleep significantly after sunrise. However, surprisingly, MSFsc did not correlate with daily light intensity at the different geographical locations. Although these findings appear to contradict earlier studies suggesting that in the wider population increased light exposure is associated with an earlier chronotype, our findings are derived exclusively from a student population aged between 17 and 26 years. We therefore suggest that the age and occupation of our population increase the likelihood that these individuals will experience relatively little light exposure in the morning whilst encountering more light exposure later in the day, when light has a delaying effect upon the circadian system.

Sweet basil (<i>Ocimum basilicum L.</i>) is primarily used for culinary purposes, but it is also used in the fragrance and medicinal industries. In the last few years, global sweet basil production has been significantly impacted by downy mildew caused by <i>Peronospora belbahrii</i>. Nighttime exposure to red light has been shown to inhibit sporulation of <i>P. belbahrii</i>. The objective of this study was to determine if nighttime exposure to red light from light-emitting diodes (LEDs; λ<sub>max</sub> = 625 nm) could increase plant growth (plant height and leaf size) and yield (number and weight of leaves) in basil plants. In two sets of greenhouse experiments, red light was applied at a photosynthetic photon flux density (PPFD) of 60 µmol m<sup>-2</sup> s<sup>-1</sup> during the otherwise dark night for 10 hours (from 20:00 to 06:00). The results demonstrate that exposure to red light at night can increase the number of basil leaves per plant, plant height, leaf size (length and width), and leaf fresh and dry weight, compared to plants in darkness at night. The addition of incremental red light at night has the potential to be cost-effective for fresh organic basil production in controlled environments.

In Istanbul, one of the most densely populated cities of Turkey, the population has grown rapidly over the last 30 years. In addition to being one of the rapidly flourishing cities in Europe, the city is positioned on the seismically active North Anatolian Fault (NAF). The form and rate of Istanbul’s fast urban growth has serious implications for seismic hazards. There have been some studies to map lateral urban growth for the city but they do not give satisfactory information about vertical urban growth and seismic hazards. We use DMSP night lights and Landsat data to map changes in land cover-land use in and around the city since 1984, and determine relations of these changes with the NAF. Changes in land use and intensity of development are identified by changes in night light brightness while changes in land cover are identified by changes in land surface reflectance. Aggregate changes in reflectance are represented as changes in subpixel mixtures of the most functionally and spectrally distinct spectral endmembers of land cover. Using standardized global endmembers, SVD composite images were produced for 1984, 2000 and 2011 and fraction change (δSVD) maps were produced for the decadal intervals. The results show that most of the urban expansion has occurred near the NAF. This has serious implications for seismic hazards in the future if the progression of large earthquakes continues to move westward toward the city.

Rapid expansion of human activity has driven well-documented shifts in the spatial distribution of wildlife, but the cumulative effect of human disturbance on the temporal dynamics of animals has not been quantified. We examined anthropogenic effects on mammal diel activity patterns, conducting a meta-analysis of 76 studies of 62 species from six continents. Our global study revealed a strong effect of humans on daily patterns of wildlife activity. Animals increased their nocturnality by an average factor of 1.36 in response to human disturbance. This finding was consistent across continents, habitats, taxa, and human activities. As the global human footprint expands, temporal avoidance of humans may facilitate human-wildlife coexistence. However, such responses can result in marked shifts away from natural patterns of activity, with consequences for fitness, population persistence, community interactions, and evolution.